获取返回值从Task.Run [英] Getting return value from Task.Run

问题描述

我这里有下面的代码

    public static async Task<string> Start(IProgress<ProcessTaskAsyncExProgress> progress)
    {
        const int total = 10;
        for (var i = 0; i <= total; i++)
        {
            await Task.Run(() => RunLongTask(i.ToString(CultureInfo.InvariantCulture)));
            if (progress != null)
            {
                var args = new ProcessTaskAsyncExProgress
                {
                    ProgressPercentage = (int)(i / (double)total * 100.0),
                    Text = "processing " + i
                };
                progress.Report(args);
            }
        }
        return "Done";
    }

    private static string RunLongTask(string taskName)
    {
        Task.Delay(300);
        return taskName + "Completed!";
    }

在这一行：

await Task.Run(() => RunLongTask(i.ToString(CultureInfo.InvariantCulture)));

我如何找回RunLongTask的字符串值？

How do I get back the string value of RunLongTask?

我试过

var val = await Task.Run(() => RunLongTask(i.ToString(CultureInfo.InvariantCulture))).Result;

不过，我得到一个错误字符串不awaitable

But I get an error "string is not awaitable"

推荐答案

删除结果从末尾。当你的await 您将获得结果从的await-能够方法了。

Remove the Result from the end. When you await you will get the Result back from the await-able method.

var val = await Task.Run(() => RunLongTask(i.ToString(CultureInfo.InvariantCulture)));

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